Answer:
(D)
Step-by-step explanation:
Given: It is given that ∠6 measures 140°.
To find: The measure of ∠1.
Solution:
It is given that ∠6 measures 140° and since there are two parallel lines which are cut by a transversal, then using the properties of parallel lines, we have
m∠6=m∠2(Alternate interior angles)
Therefore, m∠6=m∠2=140°
Also, m∠2 and m∠1 forms the linear pair, therefore
m∠1+m∠2=180°(Linear pair)
⇒m∠1+140°=180°
⇒m∠1=180-140
⇒m∠1=40°
Thus, the measure of ∠1 is 40°.
Hence, option D is correct.